Typical over-the-needle i.v. catheter assemblies require the removal and disposal of a contaminated needle after the needle tip and catheter have been inserted into a blood vessel of a patient. Since at the time a needle is withdrawn, the user has other priorities, needles tend to be temporarily discarded for later disposal. This leads to the possibility of accidental scratching or pricking of health personnel which can lead to inadvertent infection with viruses such as HIV and hepatitis.
For this reason various attempts have been made to provide catheter assemblies incorporating various means for preventing a needle tip from coming into inadvertent contact with a user once the cannula hub of the catheter assembly has been left in situ in the patient.
One problem experienced with assemblies of this type is to provide a needle protector which protects the needle both before and after use by using the same elongate protector body. This body should allow a needle and needle hub to be assembled with a cannula and cannula hub within the protector body, said assembly being extended by sliding the same in the body to a position where the cannula hub is free of the protector as, for example, when inserted into a patient. The needle is then retracted within the body of the needle protector for safety.
Prior Art systems, however, allow the cannula hub and protector to be separated without initiating the withdrawal of the needle protector, thereby allowing the needle to become exposed if the device is not utilised properly.
In U.S. Pat. No. 5,019,049, there is described an assembly of an intravenous cannula insertion device and an elongate needle protector, said protector comprising;
a slotted tube, PA1 a needle and needle hub, said hub comprising a fin protruding through said slot to allow the needle and needle hub assembly to be moved within said protector, PA1 a cannula hub operatively inter-engagable with said needle hub within said protector, whereby said needle hub and said cannula hub are slidable together in the protector to allow i.v. insertion of the cannula and wherein said assembly includes retraction prevention means for preventing the retraction of the cannula hub after it has been fully extended for use.